The assessment of disease activity in takayasu arteritis

Objectives: The aim of this study is to analyze the activity parameters that affect the physicians' global opinion (PGO) in TA. Methods: The demographic and clinical data of patients with TA who were followed in the Rheumatology clinic at Dokuz Eylul University were retrospectively evaluated. Disease activity was assessed using various tools, including National İnstitutes of Healty (NIH) criteria, disease extent index-Takayasu (DEI.Tak), the Indian Takayasu Activity Score (ITAS2010), PGO, radiological activity parameters, and acute-phase reactants at every 3-6 months.According to the TA follow-up protocol of the Rheumatology and Radiology Board of our hospital, the patients were followed using 3-6 monthly B-mode/Doppler ultrasonography (USG) examinations and 6-12 monthly magnetic resonance imaging (MRI) examinations with MRA.The agreement between disease activity parameters were assessed by kappa coefficient and Spearman rank correlation. Results: In total, 52 patients (48 females; mean age: 46.8±13.2 years) who fulfilled the American College of Rheumatology (ACR) criteria for TA were enrolled in this study. Their mean disease duration was 9.7±7.6 years and mean follow-up duration was 6.4±2.9 years. 33 (63.5%) patients had type 5 TA and 13 (25%) had type 1 TA. 40 (76.9%) patients were categorized as having active disease in their first visits according to PGO. In the last visit, 31 (59.6%) patients hadinactive disease, 19 (36.5%) had persistent disease and two (%3.9) had active disease. All the patients used the long-term glucocorticoid therapy and DMARD/immunosuppressive drugs. Six (%11.5) of them were on the treatment with biologics. Six (11.5%) patients underwent vascular surgery and 26 (50%) were performed endovascular repair for arterial stenosis. In total, 360 visits of 52 patients were evaluated. PGO was that the disease was inactive in the 181 visits, persistan in the 99 visits and active in the 80 visits. To obtain more clear results, visits with persistan disease were excluded and final evaluation included the 261 visits of 52 TA patients. Correlations of the activity parameters with each other and PGO were evaluated. The highest aggreement was found between PGO and the results of MRA and also B-mode / Doppler USG (=0.80 and =0.79, respectively). NIH activation, DEI.Tak and ITAS2010 scores also well correlated with PGO (=0.64, r=0.54 and r=0.55, respectively). There was a poor agreement between PGO and hs-CRP (=0.32). Conclusions: The results of this study suggest that imaging had a significant impact on physician's decision regarding disease activity in TA. Although disease activity scores including NIH, DEI-Tak and ITAS2010 were well correlated with each other, there was a poor agreement between CRP and all the other activity parameters.